One vertex per element, one color per generator, with an edge from x to x·s.
(9,10,15,18)(11,19,21,14)(12,17,13,16)(20,23,22,24)(25,26)(27,33)(28,32)(29,30)(31,35)(34,39)(36,37)(38,40)(1,2)(3,5)(4,6)(7,8)(9,11)(10,14)(12,20)(13,22)(15,21)(16,23)(17,24)(18,19)(26,30)(31,33)(32,37)(38,39) involution — undirected(1,2,4,6)(3,5,7,8)(9,12,15,13)(10,16,18,17)(11,20,21,22)(14,23,19,24)(25,26)(27,31)(28,32)(29,30)(33,35)(34,38)(36,37)(39,40)(3,7)(5,8)(9,13,15,12)(10,17,18,16)(11,20,21,22)(14,23,19,24)(25,27,29,35)(26,31,30,33)(28,34,36,40)(32,38,37,39)(1,2)(3,5)(4,6)(7,8)(9,11)(10,14)(12,22)(13,20)(15,21)(16,24)(17,23)(18,19)(25,28,29,36)(26,32,30,37)(27,34,35,40)(31,38,33,39)(1,3)(2,5)(4,7)(6,8)(9,14)(10,11)(12,23)(13,24)(15,19)(16,20)(17,22)(18,21) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.